KiCAD 8: create symbol for Rohm complementary MOSFET pair US6M2

RE: KiCAD 8: create symbol for Rohm complementary MOSFET pair US6M2

Jan Cumps — Fri, 20 Sep 2024 19:17:13 GMT

It's common for P-channel MOSFETs to have different characteristics than their N-channel counterpart. Here, where the two are sitting in one package, it's easy to compare:

RE: KiCAD 8: create symbol for Rohm complementary MOSFET pair US6M2

Jan Cumps — Tue, 17 Sep 2024 16:00:00 GMT

This is the type of connector I may try to forge:

source: KiCAD forum

A slot in the motherboard, with pads on top and bottom, both sides of the slot. My board having corresponding pads.
You slide the board in, vertically, and solder all 4 corners..

Mechanically, this isn't strong. Solder and pads aren't made to take mechanical strain and vibrations. And once mounted it's permanent. The connection reliability, on the other hand, is excellent.

RE: KiCAD 8: create symbol for Rohm complementary MOSFET pair US6M2

Jan Cumps — Mon, 16 Sep 2024 19:44:23 GMT

A little layout exercise: power supply filtering and the Q1 part:

Blue is the digital domain, yellow the analogue.

I'm going for a 4-layer board - the microcontroller section will need it if I want a reasonable separation between the domains. Top layer digital signal, bottom layer analogue signal. 2 middle layers power.

RE: KiCAD 8: create symbol for Rohm complementary MOSFET pair US6M2

shabaz — Sun, 15 Sep 2024 00:33:51 GMT

Thought I'd have some fun with Python. This shape is unfortunately not part of the KiCad palette, but, I wrote a program to generate either full ovals, or half-ovals. I imported your symbol, and then added half-ovals.

I don't know if it's a good idea or not, since normally MOSFETs would never have a half-oval! So it is unorthodox. Anyway it was just an experiment, in case future symbols need such shapes. Maybe for tubes/vaves is more normal! : )

Half-square or half-rectangle are already possible with KiCad, simply by using the Add Lines tool and drawing it, and then optionally filling it.

Using the Python program is simple; first decide on the width and height of the full oval, then run the program as follows (omit the 'split' parameter if you want a full oval instead of a half oval):

It will generate a symbol file that can be imported in just like any normal symbol, and then copy-paste from there into your desired actual symbol.

RE: KiCAD 8: create symbol for Rohm complementary MOSFET pair US6M2

shabaz — Sat, 14 Sep 2024 20:58:11 GMT

Second version for sure.

Incidentally, unrelated, I saw this part: DMC2700UDM-7 ( https://uk.farnell.com/diodes-inc/dmc2700udm-7/mosfet-dual-n-p-ch-20v-1-34a/dp/3944032 ) which is currently in-stock and is SOT23-6 packaged. Fairly similar specs, although there are some differences. But has a different pinout : ( so it wouldn't be possible to have the same footprint for both parts. Anyway though it worth mentioning in case the first part is hard to find.